In many industries, particularly in the automotive refinish industry, customers demand not only special color effects and good color match, but also exceptionally good appearance and durability. In refinishing cars in the field, portable colorimeters are commonly used to measure the target color readings off the coating on a car body being repaired, followed by searching through stored databases of paint formulas to find an existing formula that is the closest match with the color readings measured off the car body. Such a process allows a body shop to directly find the best paint formula to match the car being repaired. However, these current processes require creation and maintenance of an extensive database containing thousands of refinish car colors from which one can after exhaustive search select a color match that is closest to the target coating. Moreover, the aforedescribed selection process is expensive since the refinisher has to make and test several paint samples before a close match to the target coating can be achieved. The present invention helps in producing the closest color matches in a cost-effective manner without the need for creating and maintaining an extensive color database.
A method of characterizing a color coating on a surface, such as an auto body, has been disclosed in U.S. Pat. No. 5,231,472. The method utilized measures the reflectance of a reflected light attenuated by the presence of metal flakes typically used in metallic paints. Several solutions to radiative transfer equations of S. Chandrasekhar correlate the attenuated measured reflectances from a target metallic coating with those predicted by the solutions to produce a close color match for the target metallic coating.